Setting up separate profiles involves a visit to the Google Home app, where users must say "OK Google" and "Hey Google" twice apiece. Google then analyzes the voice on its neural network and downloads the characteristics to the speaker, so it can analyze hotwords locally instead of wasting time sending them to the cloud. The feature is rolling out to U.S. users starting today, and will expand to U.K. users in the "coming months." Your move, Amazon Echo.